CO-DETECTION OF HELICOBACTER-PYLORI AND OF ITS RESISTANCE TO CLARITHROMYCIN BY PCR

Our aim was to develop a rapid molecular test based on polymerase chai n reaction-restriction fragment length polymorphism (PCR-RFLP) and mak ing it possible to detect Helicobacter pylori directly from gastric bi opsy samples, and to test its susceptibility to clarithromycin. A 629- bp fragment of the 23S rRNA gene of H. pylori H. was amplified by PCR and the mutations responsible for clarithromycin resistance were detec ted with BsaI and BbsI restriction endonucleases. Thirty-five gastric samples were tested in parallel by standard microbiologic methods (cul ture and clarithromycin susceptibility testing with E-test strips) and by PCR-RFLP. The 10 culture-negative samples were also PCR-negative. Sixteen out of the 25 culture positive samples (64%) were PCR-positive . RFLP analysis could be done in 12 cases and the results were in agre ement with those of the E-test: susceptibility in five cases, resistan ce in seven (six A2144G mutations and one A2143G mutation). (C) 1998 F ederation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.